C3 and paroxysmal nocturnal hemoglobinuria: When the intravascular hemolysis of PNH has been controlled with C5 inhibitors (e.g., eculizumab and ravulizumab), extravascular hemolysis in the liver and spleen can develop as terminal complement pathway blockade increases the availability of C3b-opsonized PNH red blood cells and targets them for extravascular hemolysis [1,3,14].